/Engine/Source/Runtime/Engine/Classes/Animation/AnimSequence.h
Get Bone Transform of the base (reference) pose of the additive animation for the Time given, relative to Parent for all RequiredBones
void GetAdditiveBasePose ( [FCompactPose](API\Runtime\Engine\FCompactPose) & OutPose, [FBlendedCurve](API\Runtime\Engine\Animation\FBlendedCurve) & OutCurve, const [FAnimExtractContext](API\Runtime\Engine\Animation\FAnimExtractContext) & ExtractionContext ) const